I've worked on projects that were specced and goals agreed with funders five years before delivery, and two years before any technical or user-focussed specification or development began, and I wouldn't be surprised if something similar happened with NMOLP.

To develop for the X360 and Ps3 you know exactly what each system is going to be specced at, and are able to develop specifically to those specifications and are thus able to focus more man hours on the design and game play side of the game as opposed to the nitty-gritty tech side of getting the game to run on all these different platforms with the PC.